Hispidulin Inhibits the Vascular Inflammation Triggered by Porphyromonas gingivalis Lipopolysaccharide.

Hispidulin is a natural bioactive flavonoid that has been studied for its potential therapeutic properties, including its anti-inflammatory, antioxidant, and neuroprotective effects. The aim of this study was to explore whether hispidulin could inhibit the endothelial inflammation triggered by Porphyromonas gingivalis (P. gingivalis) lipopolysaccharide (LPS). The adhesion of monocytes to the vascular endothelium was evaluated through in vitro and ex vivo monocyte adhesion assays. We analyzed the migration of monocytes across the endothelial layer using a transmigration assay. The results showed that treatment with hispidulin decreased the P. gingivalis LPS-induced adhesion of monocytes to endothelial cells and their migration by suppressing the P. gingivalis LPS-triggered expression of intercellular adhesion molecule-1 (ICAM-1) through downregulating nuclear factor-қB (NF-қB). In addition, hispidulin inhibited P. gingivalis LPS-induced mitogen-activated protein kinases (MAPKs) and AKT in endothelial cells. Altogether, the results indicate that hispidulin suppresses the vascular inflammation induced by P. gingivalis LPS. Mechanistically, it prevents the adhesion of monocytes to the vascular endothelium and migration and inhibits NF-қB, MAPKs, and AKT signaling in endothelial cells.

Differential virulence of infectious hematopoietic necrosis virus (IHNV) isolated from salmonid fish in Gangwon Province, Korea.

The present study investigated the virulence and expression of innate immunity genes in isolates of infectious hematopoietic necrosis virus (IHNV) in Gangwon province, South Korea, by challenging rainbow trout, Atlantic salmon, and coho salmon. Eight IHNV isolates were used to infect RTG-2 cells for viral replication using plaque assays. Three isolates with the highest replication rates, the RtPc0314g and RtPc0314c isolates of the JRt-Shizuoka type and the RtPc0816g isolate of the JRt-Nagano type, were experimentally infected into the fish. In rainbow trout, both RtPc0314c and RtPc0314g isolates showed 100% cumulative mortality while the RtPc0816g isolate showed 60% cumulative mortality for 14 days. In contrast, all three isolates showed <60% cumulative mortality in Atlantic salmon and coho salmon. The expression of G genes in the kidney was higher than that in the spleen-infected fish, with the highest expression observed in the kidneys of rainbow trout. The relative expression levels of innate immunity genes were higher in rainbow trout than in Atlantic salmon and coho salmon. The expression level of immunoglobulin M increased until day 7, and the expression of type I interferon was higher in the spleen than in other tissues. The expression of Mx-1 was higher in the kidney and liver than other tissues. These results indicate that IHNV isolates from Gangwon province show host-specific virulence in rainbow trout and that their virulence and replication were higher in JRt-Shizuoka type than in JRt-Nagano type isolates.

Anti-Aging Effect of the Ketone Metabolite ß-Hydroxybutyrate in Drosophila Intestinal Stem Cells.

Age-related changes in tissue-resident adult stem cells may be closely linked to tissue aging and age-related diseases, such as cancer. ß-Hydroxybutyrate is emerging as an important molecule for exhibiting the anti-aging effects of caloric restriction and fasting, which are generally considered to be beneficial for stem cell maintenance and tissue regeneration. The effects of ß-hydroxybutyrate on adult stem cells remain largely unknown. Therefore, this study was undertaken to investigate whether ß-hydroxybutyrate supplementation exerts beneficial effects on age-related changes in intestinal stem cells that were derived from the Drosophila midgut. Our results indicate that ß-hydroxybutyrate inhibits age- and oxidative stress-induced changes in midgut intestinal stem cells, including centrosome amplification (a hallmark of cancers), hyperproliferation, and DNA damage accumulation. Additionally, ß-hydroxybutyrate inhibits age- and oxidative stress-induced heterochromatin instability in enterocytes, an intestinal stem cells niche cells. Our results suggest that ß-hydroxybutyrate exerts both intrinsic as well as extrinsic influence in order to maintain stem cell homeostasis.

The anti-aging effect of vitamin D and vitamin D receptor in Drosophila midgut.

Adult stem cells are pivotal for maintaining tissue homeostasis, and their functional decline is linked to aging and its associated diseases, influenced by the niche cells' environment. Age- and cancer-related reduction of vitamin D and its receptor levels are well documented in human clinical studies. However, the mechanisms through which the vitamin D/vitamin D receptor pathway contributes to anti-aging and extends life expectancy are not well understood. In this study, we aimed to determine the protective role of the vitamin D/vitamin D receptor pathway in differentiated enterocytes (ECs) during intestinal stem cell (ISC) aging. By utilizing a well- established Drosophila midgut model for stem cell aging biology, we revealed that vitamin D receptor knockdown in ECs induced ISC proliferation, EC death, ISC aging, and enteroendocrine cell differentiation. Additionally, age- and oxidative stress-induced increases in ISC proliferation and centrosome amplification were reduced by vitamin D treatment. Our findings suggest a direct evidence of the anti-aging role of the vitamin D/vitamin D receptor pathway and provides insights into the molecular mechanisms underlying healthy aging in Drosophila.

Computer simulation approach to the identification of visfatin-derived angiogenic peptides.

Angiogenesis plays an essential role in various normal physiological processes, such as embryogenesis, tissue repair, and skin regeneration. Visfatin is a 52 kDa adipokine secreted by various tissues including adipocytes. It stimulates the expression of vascular endothelial growth factor (VEGF) and promotes angiogenesis. However, there are several issues in developing full-length visfatin as a therapeutic drug due to its high molecular weight. Therefore, the purpose of this study was to develop peptides, based on the active site of visfatin, with similar or superior angiogenic activity using computer simulation techniques.Initially, the active site domain (residues 181∼390) of visfatin was first truncated into small peptides using the overlapping technique. Subsequently, the 114 truncated small peptides were then subjected to molecular docking analysis using two docking programs (HADDOCK and GalaxyPepDock) to generate small peptides with the highest affinity for visfatin. Furthermore, molecular dynamics simulations (MD) were conducted to investigate the stability of the protein-ligand complexes by computing root mean square deviation (RSMD) and root mean square fluctuation(RMSF) plots for the visfatin-peptide complexes. Finally, peptides with the highest affinity were examined for angiogenic activities, such as cell migration, invasion, and tubule formation in human umbilical vein endothelial cells (HUVECs). Through the docking analysis of the 114 truncated peptides, we screened nine peptides with a high affinity for visfatin. Of these, we discovered two peptides (peptide-1: LEYKLHDFGY and peptide-2: EYKLHDFGYRGV) with the highest affinity for visfatin. In an in vitrostudy, these two peptides showed superior angiogenic activity compared to visfatin itself and stimulated mRNA expressions of visfatin and VEGF-A. These results show that the peptides generated by the protein-peptide docking simulation have a more efficient angiogenic activity than the original visfatin.

Reduced expression of FASN through SREBP-1 down-regulation is responsible for hypoxic cell death in HepG2 cells.

Cells under hypoxic stress either activate an adaptive response or undergo cell death. Although some mechanisms have been reported, the exact mechanism behind hypoxic cell death remains unclear. Recently, increased expression of fatty acid synthase (FASN) has been observed in various human cancers. In highly proliferating cells, tumor-associated FASN is considered necessary for both membrane lipids production and post-translational protein modification, but the exact mechanisms are not fully understood. Further, FASN overexpression is associated with aggressive and malignant cancer diseases and FASN inhibition induces apoptosis in cancer cells. For this reason, FASN is emerging as a key target for the potential diagnosis and treatment of various cancers. Here, we observed decreased FASN expression under hypoxic cell death conditions in HepG2 cells. Thus, we examined the effect of decreased FASN expression on hypoxia-induced cell death in HepG2 cells and also investigated the mechanism responsible for reduction of FASN expression under hypoxic cell death conditions. As a result, reduction of FASN expression resulted in hypoxic cell death via malonyl-CoA accumulation. In addition, SREBP-1 restored FASN reduction and hypoxia-induced apoptosis. Taken together, we suggest that hypoxic cell death is promoted by the reduced expression of FASN through SREBP-1 down-regulation.

Human ZNF312b oncogene is regulated by Sp1 binding to its promoter region through DNA demethylation and histone acetylation in gastric cancer.

In a previous study, human ZNF312b was identified as a cell proliferation-associated oncogene via the K-ras/extracellular signal-regulated kinase cascade in gastric cancer. However, the mechanism concerning its transcriptional activation remains unknown. Here, we show that DNA methylation and histone acetylation of the ZNF312b promoter function as a switch for ZNF312b transcriptional activation in gastric cancer. The transcription level of ZNF312b was increased by treatment with a demethylating agent, 5-aza-2'-deoxycytidine and the histone deacetylase inhibitor sodium butyrate, in several human cancer cell lines including gastric cancer. Consistent with these results, epigenetic analysis, such as pyrosequencing, bisulfate sequencing and methyl-specific polymerase chain reaction (MSP), showed that the expression level of ZNF312b is highly dependent on the degree of DNA methylation in gastric cancer cell lines. In addition, by ChIP assay using anti-acetyl/methyl H3K9 antibodies, histone acetylation was shown to mediate the expression of the ZNF312b gene. Interestingly, ChIP assay using the Sp1 antibody revealed that the binding of transcription factor Sp1 to the ZNF312b promoter for its transcriptional activation requires DNA demethylation and histone acetylation. Moreover, a knockdown of Sp1 resulted in a decrease in ERK-mediated proliferation via downregulation of the ZNF312b gene in gastric cancer cells. Taken together, these results suggest that the aberrant expression of ZNF312b promotes gastric tumorigenesis through epigenetic modification of its promoter region and provides a molecular mechanism for ZNF312b expression to contribute to the progression of gastric cancer.

Coenzyme Q10 decreases basic fibroblast growth factor (bFGF)-induced angiogenesis by blocking ERK activation.

Coenzyme Q10 (CoQ10) is an essential factor of the mitochondrial respiratory chain and has effective antioxidant properties. Therefore, CoQ10 has been used in a variety of clinical applications and used as a nutritional supplement to treat several human diseases. Here, we tested the effects of CoQ10 on angiogenesis stimulated by basic fibroblast growth factor (bFGF). CoQ10 significantly inhibited bFGF-induced angiogenesis in a mouse Matrigel plug and the sprouting of endothelial cells in rat aortic rings. In addition, CoQ10 decreased the ability of tube formation, migration, and invasion in endothelial cells. When CoQ10 was used to inhibit angiogenesis in endothelial cells, the expression of vascular endothelial growth factor (VEGF) and the phosphorylation of ERK were decreased. Taken together, these results indicate that CoQ10 is able to act as an antiangiogenic regulator, and its inhibitory activity is mediated by blocking an ERK-dependent pathway. This study suggests that CoQ10 may be used a therapeutic agent to decrease neovascularization in several diseases, including solid tumors.

SSeCKS regulates angiogenesis and tight junction formation in blood-brain barrier.

The blood-brain barrier (BBB) is essential for maintaining brain homeostasis and low permeability. BBB maintenance is important in the central nervous system (CNS) because disruption of the BBB may contribute to many brain disorders, including Alzheimer disease and ischemic stroke. The molecular mechanisms of BBB development remain ill-defined, however. Here we report that src-suppressed C-kinase substrate (SSeCKS) decreases the expression of vascular endothelial growth factor (VEGF) through AP-1 reduction and stimulates expression of angiopoietin-1 (Ang-1), an antipermeability factor in astrocytes. Conditioned media from SSeCKS-overexpressing astrocytes (SSeCKS-CM) blocked angiogenesis in vivo and in vitro. Moreover, SSeCKS-CM increased tight junction proteins in endothelial cells, consequently decreasing [3H]sucrose permeability. Furthermore, immunoreactivity to SSeCKS gradually increased during the BBB maturation period, and SSeCKS-expressing astrocytes closely interacted with zonula occludens (ZO)-1-expressing blood vessels in vivo. Collectively, our results suggest that SSeCKS regulates BBB differentiation by modulating both brain angiogenesis and tight junction formation.

Cancer Stem-Like Phenotype of Mitochondria Dysfunctional Hep3B Hepatocellular Carcinoma Cell Line.

Mitochondria are major organelles that play various roles in cells, and mitochondrial dysfunction is the main cause of numerous diseases. Mitochondrial dysfunction also occurs in many cancer cells, and these changes are known to affect malignancy. The mitochondria of normal embryonic stem cells (ESCs) exist in an undifferentiated state and do not function properly. We hypothesized that mitochondrial dysfunction in cancer cells caused by the depletion of mitochondrial DNA might be similar to the mitochondrial state of ESCs. We generated mitochondria dysfunctional (ρ0) cells from the Hep3B hepatocellular carcinoma cell line and tested whether these ρ0 cells show cancer stem-like properties, such as self-renewal, chemotherapy resistance, and angiogenesis. Compared with Hep3B cells, the characteristics of each cancer stem-like cell were increased in Hep3B/ρ0 cells. The Hep3B/ρ0 cells formed a continuous and large sphere from a single cell. Additionally, the Hep3B/ρ0 cells showed resistance to the anticancer drug doxorubicin because of the increased expression of ATP-binding cassette Subfamily B Member 1. The Hep3B/ρ0 conditioned medium induced more and thicker blood vessels and increased the mobility and invasiveness of the blood vessel cells. Therefore, our data suggest that mitochondrial dysfunction can transform cancer cells into cancer stem-like cells.

Thromboxane A(2) increases endothelial permeability through upregulation of interleukin-8.

Thromboxane A(2) (TXA(2)), a major prostanoid formed from prostaglandin H(2) by thromboxane synthase, is involved in the pathogenesis of a variety of vascular diseases. In this study, we report that TXA(2) mimetic U46619 significantly increases the endothelial permeability both in vitro and in vivo. U46619 enhanced the expression and secretion of interleukin-8 (IL-8), a major inducer of vascular permeability, in endothelial cells. Promoter analysis showed that the U46619-induced expression of IL-8 was mainly regulated by nuclear factor-kappaB (NF-kappaB). U46619 induced the activation of NF-kappaB through IkappaB kinase (IKK) activation, IkappaB phosphorylation and NF-kappaB nuclear translocation. Furthermore, the inhibition of IL-8 or blockade of the IL-8 receptor attenuated the U46619-induced endothelial cell permeability by modulating the cell-cell junctions. Overall, these results suggest that U46619 promotes vascular permeability through the production of IL-8 via NF-kappaB activation in endothelial cells.

Melatonin suppresses tumor angiogenesis by inhibiting HIF-1alpha stabilization under hypoxia.

Angiogenesis is an important mediator of tumor progression. As tumors expand, diffusion distances from the existing vascular supply increases, resulting in hypoxia in the cancer cells. Sustained expansion of a tumor mass requires new blood vessel formation to provide rapidly proliferating tumor cells with an adequate supply of oxygen and nutrients. The key regulator of hypoxia-induced angiogenesis is the transcription factor known as hypoxia-inducible factor (HIF)-1. HIF-1alpha is stabilized by hypoxia-induced reactive oxygen species (ROS) and enhances the expression of several types of hypoxic genes, including that of the angiogenic activator known as vascular endothelial cell growth factor (VEGF). In this study, we found that melatonin, a small lipophilic molecule secreted primarily by the pineal gland, destabilizes hypoxia-induced HIF-1alpha protein levels in the HCT116 human colon cancer cell line. This destabilization of HIF-1alpha resulted from the antioxidant activity of melatonin against ROS induced by hypoxia. Moreover, under hypoxia, melatonin suppressed HIF-1 transcriptional activity, leading to a decrease in VEGF expression. Melatonin also blocked in vitro tube formation and invasion and migration of human umbilical vein endothelial cells induced by hypoxia-stimulated conditioned media of HCT116 cells. These findings suggest that melatonin could play a pivotal role in tumor suppression via inhibition of HIF-1-mediated angiogenesis.

C-terminal truncated HBx reduces doxorubicin cytotoxicity via ABCB1 upregulation in Huh-7 hepatocellular carcinoma cells.

Hepatitis B virus (HBV) encoding the HBV x protein (HBx) is a known causative agent of hepatocellular carcinoma (HCC). Its pathogenic activities in HCC include interference with several signaling pathways associated with cell proliferation and apoptosis. Mutant C-terminal-truncated HBx isoforms are frequently found in human HCC and have been shown to enhance proliferation and invasiveness leading to HCC malignancy. We investigated the molecular mechanism of the reduced doxorubicin cytotoxicity by C-terminal truncated HBx. Cells transfected with C-terminal truncated HBx exhibited reduced cytotoxicity to doxorubicin compared to those transfected with full-length HBx. The doxorubicin resistance of cells expressing C-terminal truncated HBx correlated with upregulation of the ATP binding cassette subfamily B member 1(ABCB1) transporter, resulting in the enhanced efflux of doxorubicin. Inhibiting the activity of ABCB1 and silencing ABCB1 expression by small interfering ribonucleic acid (siRNA) increased the cytotoxicity of doxorubicin. These results indicate that elevated ABCB1 expression induced by C-terminal truncation of HBx was responsible for doxorubicin resistance in HCC. Hence, co-treatment with an ABCB1 inhibitor and an anticancer agent may be effective for the treatment of patients with liver cancer containing the C-terminal truncated HBx. [BMB Reports 2019; 52(5): 330-335].

KR-31831, benzopyran derivative, inhibits VEGF-induced angiogenesis of HUVECs through suppressing KDR expression.

Angiogenesis is important in the development and progression of cancer, therefore the therapeutic approach based on anti-angiogenesis may represent a promising therapeutic option. KR-31831 is a novel anti-ischemic agent. Previously, we reported the anti-angiogenic activity of KR-31831. In the present study we investigated the molecular mechanisms underlying anti-angiogenic activity of KR-31831. We show that KR-31831 inhibits vascular endothelial growth factor (VEGF)-induced proliferation and tube formation via release of intracellular Ca2+ and phosphorylation of extra-cellular regulated kinase 1/2 (Erk 1/2) in human umbilical vein endothelial cells (HUVECs). Moreover, the expression of VEGF receptor 2 (VEGFR2, known as Flk-1 or KDR) was reduced by the treatment of KR-31831. These results suggest that KR-31831 may have inhibitory effects on tumor angiogenesis through down-regulation of KDR expression.

Mitochondrial dysfunction suppresses p53 expression via calcium-mediated nuclear factor-kB signaling in HCT116 human colorectal carcinoma cells.

Mitochondrial DNA (mtDNA) mutations are often observed in various cancer types. Although the correlation between mitochondrial dysfunction and cancer malignancy has been demonstrated by several studies, further research is required to elucidate the molecular mechanisms underlying accelerated tumor development and progression due to mitochondrial mutations. We generated an mtDNA-depleted cell line, ρ°, via long-term ethidium bromide treatment to define the molecular mechanisms of tumor malignancy induced by mitochondrial dysfunction. Mitochondrial dysfunction in ρ° cells reduced drug-induced cell death and decreased the expression of pro-apoptotic proteins including p53. The p53 expression was reduced by activation of nuclear factor-κB that depended on elevated levels of free calcium in HCT116/ρ° cells. Overall, these data provide a novel mechanism for tumor development and drug resistance due to mitochondrial dysfunction. [BMB Reports 2018; 51(6): 296-301].

Thymosin {beta}(10) inhibits angiogenesis and tumor growth by interfering with Ras function.

Thymosin beta(10) is a monomeric actin sequestering protein that regulates actin dynamics. Previously, we and others have shown that thymosin beta(10) acts as an actin-mediated tumor suppressor. In this study, we show that thymosin beta(10) is not only a cytoskeletal regulator, but that it also acts as a potent inhibitor of angiogenesis and tumor growth by its interaction with Ras. We found that overexpressed thymosin beta(10) significantly inhibited vascular endothelial growth factor-induced endothelial cell proliferation, migration, invasion, and tube formation in vitro. Vessel sprouting was also inhibited ex vivo. We further show that thymosin beta(10) directly interacted with Ras. This interaction resulted in inhibition of the Ras downstream mitogen-activated protein kinase/extracellular signal-regulated kinase kinase signaling pathway, leading to decreased vascular endothelial growth factor production. Thymosin beta(10) injected into a xenograft model of human ovarian cancer in nude mice markedly inhibited tumor growth and reduced tumor vascularity. In contrast, a related thymosin family member, thymosin beta(4), did not bind to Ras and showed positive effects on angiogenesis. These findings show that the inhibition of Ras signal transduction by thymosin beta(10) results in antiangiogenic and antitumor effects, suggesting that thymosin beta(10) may be valuable in anticancer therapy.

Anti-angiogenic action of plasma hyaluronan binding protein in human umbilical vein endothelial cells.

The kringle domain is a triple loop structure present in angiostatin and endostatin. The disulfide bond-linked kringle architectures have been known to be essential for anti-angiogenic activity. Plasma hyaluronan binding protein (PHBP) is a novel serine protease which consists of three epidermal growth factor (EGF) domains, a kringle domain, and a serine protease domain. PHBP can be cleaved autocatalytically to generate activity and is highly expressed in the human blood and liver. To determine the anti-angiogenic activities of PHBP, we purified recombinant mouse PHBP from stable cell line overexpressing PHBP and used protein in vivo and in vitro angiogenesis assays. We found that recombinant PHBP inhibits not only angiogenesis in vivo in chorioallantoic membrane (CAM) assay but also the basic fibroblast growth factor (bFGF)-induced proliferation, invasion and tube formation of human umbilical vein endothelial cells (HUVECs) in a dose-dependant manner. Moreover, we found that the kringle domain of PHBP was essential for the anti-angiogenic action of PHBP by the deletion mutants. These findings unravel a new function of PHBP as an inhibitor of the proangiogenic phenotype of vascular endothelial cells and demonstrate that the kringle domain of PHBP might be a potent novel inhibitor of activated endothelial cells in vitro and in vivo.

Synergistic effect and condition of pegylated interferon alpha with paclitaxel on glioblastoma.

Glioblastomas are highly vascularized tumors and anti-angiogenic strategy is one of the most promising therapeutic approaches to treat brain tumors. Interferon alpha (IFN-alpha) as a single agent or combined with standard chemo-therapy has been shown to inhibit various tumors, but the effect of combination anti-angiogenic therapy on brain tumors has not been well studied. We determined the optimal dose and schedule of pegylated IFN-alpha (PEG-IFN-alpha) against U-87MG human glioblastoma cells growing orthotopically in nude mice, since several clinical trials reported that PEG-IFN-alpha administered at higher or lower doses was less effective. The group treated two times per week with injections of 10 KU of PEG-IFN-alpha for 4 weeks showed significant decreases in cell proliferation and angiogenesis. Moreover, the optimal dose and schedule of PEG-IFN-alpha determined in this study and combined with paclitaxel treatment potently inhibited tumor growth in vivo. The mechanisms of the significant therapeutic effects were most likely caused by directly inhibiting cell proliferation and angiogenesis, and rendering apoptosis increased. Specifically PEG-IFN-alpha/paclitaxel combination induced apoptosis of tumor-associated endothelial cells more than that of tumor cells. These results suggest that optimal biological dosage and scheduling of PEG-IFN-alpha and paclitaxel combination is a potent strategy for glioblastoma patients as a new synergistic anti-endothelial treatment.

Combination treatment with temozolomide and thalidomide inhibits tumor growth and angiogenesis in an orthotopic glioma model.

The chemotherapeutic agent temozolomide (TMZ) and the anti-angiogenic agent thalidomide (THD) have both demonstrated anti-tumor activity in patients with recurrent malignant glioma. Combination treatment with TMZ and THD in patients with glioblastoma multiforme (GBM) appears to be more effective than treatment with either drug alone. To investigate the mechanism of this anti-tumor effect, we examined the combined effects of TMZ and THD in a rat glioma xenograft model. We found that combination treatment markedly inhibited the growth of tumors that were orthotopically implanted into rat brains. Using proliferating cell nuclear antigen (PCNA) staining, we observed a significant decrease in cell proliferation in these tumors. CD31 staining of the microvasculature revealed a significant decrease in angiogenesis. We also found increased apoptosis in treated tumors by terminal deoxynucleotidyl-mediated deoxyuridine triphosphate nick-end labeling (TUNEL) assay. We further demonstrated that the expression of angiogenic factors, such as vascular endothelial cell growth factor (VEGF) and basic fibroblastic growth factor (bFGF), were inhibited by THD. THD also decreased the number of ED1-positive, activated macrophages or microglial cells, which produce pro-angiogenic molecules around the glioma. Taken together, these results suggest that combination treatment with TMZ and THD inhibits tumor growth via the induction of apoptosis and the inhibition of angiogenesis in a rat model and may be a promising therapy for malignant gliomas.

KR-31831, a new synthetic anti-ischemic agent, inhibits in vivo and in vitro angiogenesis.

Angiogenesis is considered to be an integral process to the growth and spread of solid tumors. Anti-angiogenesis therapy recently has been found to be one of the most promising anti-cancer therapeutic strategies. In this study, we provide several lines of evidences showing that KR-31831, a new benzopyran derivative, has anti-angiogenic activities. KR-31831 inhibited the proliferation, migration, invasion and tube formation of bovine aortic endothelial cells (BAECs), and suppressed the release of matrix metalloproteinase-2 (MMP-2) of BAECs. KR-31831 also inhibited in vivo angiogenesis in mouse Matrigel plug assay. Furthermore, the mRNA expressions of basic fibroblast growth factor (bFGF), fibroblast growth factor receptor-2 (FGFR-2), and vascular endothelial growth factor receptor-2 (VEGFR-2) were decreased by KR-31831. Taken together, these results suggest that KR-31831 acts as a novel angiogenesis inhibitor and might be useful for treating hypervascularized cancers.